message-hidden-headers

message-hidden-headers is a variable defined in `message.el'.
Its value is

("^References:" "^Face:" "^X-Face:" "^X-Draft-From:")

Documentation:
Regexp of headers to be hidden when composing new messages.
This can also be a list of regexps to match headers. Or a list
starting with `not' and followed by regexps.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.